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authorMark Rutland <mark.rutland@arm.com>2014-05-21 14:29:23 +0100
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2014-06-09 10:24:02 +0200
commitb924d586d70bd52c3648870d3313b2ea7081c83d (patch)
tree6ca0232fd6bab8e603dd3ef84a064ce5bd5b1a33
parentcb6d04d60664210d2e198192e164b6cfc8bade83 (diff)
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arm64: zero cntvoff_el2
Currently cntvoff_el2 is initialised with an arbitrary bag of bits derived from the initial value of cnthctl_el2 on the current CPU. This is somewhat odd and problematic as some of these bits are UNKNOWN at reset and may differ across CPUs (which may cause an OS at EL1 to observe time going backwards across CPUs). This patch instead initialises cntvoff_el2 with xzr, giving the register a consistent value of zero on all CPUs. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Scott Wood <scottwood@freescale.com> Cc: David Feng <fenghua@phytium.com.cn> Cc: Tom Rini <trini@ti.com> Acked-by: David.Feng <fenghua@phytium.com.cn>
-rw-r--r--arch/arm/cpu/armv8/transition.S2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/cpu/armv8/transition.S b/arch/arm/cpu/armv8/transition.S
index e0a5946..38dea5c 100644
--- a/arch/arm/cpu/armv8/transition.S
+++ b/arch/arm/cpu/armv8/transition.S
@@ -43,7 +43,7 @@ ENTRY(armv8_switch_to_el1)
mrs x0, cnthctl_el2
orr x0, x0, #0x3 /* Enable EL1 access to timers */
msr cnthctl_el2, x0
- msr cntvoff_el2, x0
+ msr cntvoff_el2, xzr
mrs x0, cntkctl_el1
orr x0, x0, #0x3 /* Enable EL0 access to timers */
msr cntkctl_el1, x0